diff --git a/core/Makefile b/core/Makefile
index c19b0754af5b9ec33e81286de177e4a0f09614ec..00b7f66ea56a0b31a3fc0734220b7d5c2b567aad 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -6902,7 +6902,7 @@ endif
 # -----------------------------------------------------------------
 # The SDK
 
-ifneq ($(filter sdk,$(MAKECMDGOALS)),)
+ifneq ($(filter sdk sdk_addon,$(MAKECMDGOALS)),)
 
 # The SDK includes host-specific components, so it belongs under HOST_OUT.
 sdk_dir := $(HOST_OUT)/sdk/$(TARGET_PRODUCT)
diff --git a/core/app_prebuilt_internal.mk b/core/app_prebuilt_internal.mk
index eb429cdd5c6dff49af6a5e9fe288c5f2aa645846..14b2b7fd015e38fb9e6c65811b4de7cfdda3cad4 100644
--- a/core/app_prebuilt_internal.mk
+++ b/core/app_prebuilt_internal.mk
@@ -250,6 +250,7 @@ ifeq ($(module_run_appcompat),true)
 	$(call appcompat-header, aapt2)
 	$(run-appcompat)
 endif  # module_run_appcompat
+	$(patch-trichrome)
 	$(sign-package)
 	# No need for align-package because sign-package takes care of alignment
 else  # LOCAL_CERTIFICATE == PRESIGNED
diff --git a/core/config.mk b/core/config.mk
index 1c8baff1ae115fc961d6df0e1903d4f2b539a258..a7d4beed084522c1a82c110aa241e98fd2a78148 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -651,6 +651,8 @@ JETIFIER := prebuilts/sdk/tools/jetifier/jetifier-standalone/bin/jetifier-standa
 
 EXTRACT_KERNEL := build/make/tools/extract_kernel.py
 
+PATCH_TRICHROME := build/make/tools/chromium_trichrome_patcher.py
+
 # Path to tools.jar
 HOST_JDK_TOOLS_JAR := $(ANDROID_JAVA8_HOME)/lib/tools.jar
 
diff --git a/core/definitions.mk b/core/definitions.mk
index 0c46de9fc6b8ffb0110178a99f50fbc7cb1c5ec2..e475790804db587fd3c9301ad2e1987fc6dadc8c 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -3845,3 +3845,8 @@ define use_soong_sdk_libraries
   $(foreach l,$(1),$(if $(filter $(l),$(SOONG_SDK_VARIANT_MODULES)),\
       $(l).sdk,$(l)))
 endef
+
+# Patch Trichrome to add cert digest at buildtime
+define patch-trichrome
+$(hide) $(PATCH_TRICHROME) $@ $(PRIVATE_CERTIFICATE)
+endef
diff --git a/core/sysprop.mk b/core/sysprop.mk
index 5ff93a13e7c806fd8b80e4114b190075f09f4004..1755e12441442015c0f79dc7140a4ab73c2c2d13 100644
--- a/core/sysprop.mk
+++ b/core/sysprop.mk
@@ -206,8 +206,15 @@ BUILD_THUMBPRINT :=
 # Define human readable strings that describe this build
 #
 
+# Spoof target build variant because Whatsapp (and maybe others)
+# is checking the "debug" pattern in the Build.DISPLAY variable.
+SPOOFED_TARGET_BUILD_VARIANT := $(TARGET_BUILD_VARIANT)
+ifeq (userdebug,$(TARGET_BUILD_VARIANT))
+    SPOOFED_TARGET_BUILD_VARIANT := user
+endif
+
 # BUILD_ID: detail info; has the same info as the build fingerprint
-BUILD_DESC := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER_FROM_FILE) $(BUILD_VERSION_TAGS)
+BUILD_DESC := e_$(TARGET_DEVICE)-$(SPOOFED_TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER_FROM_FILE) $(BUILD_VERSION_TAGS)
 
 # BUILD_DISPLAY_ID is shown under Settings -> About Phone
 ifeq ($(TARGET_BUILD_VARIANT),user)
diff --git a/core/tasks/sdk-addon.mk b/core/tasks/sdk-addon.mk
index 5097f1266f0ed5347cefca66a7e9028a08dcb254..9acbe01ae19018e7d8e8cd89b11fca1247bf65e2 100644
--- a/core/tasks/sdk-addon.mk
+++ b/core/tasks/sdk-addon.mk
@@ -122,7 +122,7 @@ $(full_target): $(sdk_addon_deps) | $(SOONG_ZIP)
 	$(hide) $(SOONG_ZIP) -o $@ -C $(dir $(PRIVATE_STAGING_DIR)) -D $(PRIVATE_STAGING_DIR)
 
 $(full_target_img): PRIVATE_STAGING_DIR := $(call append-path,$(staging),$(addon_dir_img))/images/$(TARGET_CPU_ABI)
-$(full_target_img): $(full_target) $(addon_img_source_prop) | $(SOONG_ZIP)
+$(full_target_img): $(full_target)  $(INSTALLED_USERDATAIMAGE_TARGET) $(addon_img_source_prop) | $(SOONG_ZIP)
 	@echo Packaging SDK Addon System-Image: $@
 	$(hide) mkdir -p $(dir $@)
 	cp -R $(PRODUCT_OUT)/data $(PRIVATE_STAGING_DIR)/data
diff --git a/tools/chromium_trichrome_patcher.py b/tools/chromium_trichrome_patcher.py
new file mode 100755
index 0000000000000000000000000000000000000000..bda96b3fa66cab264936722887573ddaf570a2f1
--- /dev/null
+++ b/tools/chromium_trichrome_patcher.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+
+import os
+import subprocess
+import sys
+import zipfile
+
+infilename, sign_key = sys.argv[1:]
+
+def ExtractFingerprint(cert):
+    cmd = ['openssl', 'x509', '-sha256', '-fingerprint', '-noout', '-in', cert]
+    proc = subprocess.run(cmd, stdout=subprocess.PIPE)
+    return proc.stdout.decode('utf-8').split('=')[1].replace(':', '')
+
+def patch_trichrome(infilename, sign_key):
+    orig_certdigest = "32a2fc74d731105859e5a85df16d95f102d85b22099b8064c5d8915c61dad1e0"
+    new_certdigest = ExtractFingerprint(sign_key).lower().rstrip()
+
+    with zipfile.ZipFile(infilename, 'r') as zin, zipfile.ZipFile(infilename + ".patched", 'w') as zout:
+        for info in zin.infolist():
+            data = zin.read(info.filename)
+            if info.filename == 'AndroidManifest.xml':
+                # Make sure we can find the certdigest
+                try:
+                    data.rindex(orig_certdigest.encode('utf-16-le'))
+                except:
+                    pass
+                # Replace it
+                data = data.replace(orig_certdigest.encode('utf-16-le'), new_certdigest.encode('utf-16-le'))
+            zout.writestr(info, data)
+
+    # Delete the original file
+    os.remove(infilename)
+
+    # Rename the output file to the original file name
+    os.rename(infilename + ".patched", infilename)
+
+if "Browser_" in infilename or "BrowserWebView_" in infilename:
+    patch_trichrome(infilename, sign_key)